Linerless closure

ABSTRACT

The present invention relates to a unique unitary linerless closure for closuring containers whose neck is provided with a Ushaped groove in the top wall of the container neck, the U-shaped groove having sidewalls which slant outwardly and upwardly at an angle, the closure being provided with substantially circular radially spaced ribs depending from the lower surface of the top portion of the closure, the outer walls of the ribs slanting downwardly and inwardly at the same angle, said ribs being undercut by their inner walls and adapted to sealingly engage the groove when said closure is seated on said container neck.

United States Patent 1191 Anthony July 24, 1973 LINERLESS CLOSURE3,568,871 3/1971 Livingstone 215 40 [75] Inventor: Eugene MichaelAnthony, Primary Exami"e' Dnald N Muscatine, Iowa Atmrney- Robert L.Anderson, Kenneth J Hovet et al. [73] Assignee: Darla Industries Inc.,Los Angeles,

Calif. [57] ABSTRACT 22 Filed; No 30 1971 The present invention relatesto a unique unitary linerless closure for closuring containers whoseneck is pro- [21] APPL 203,330 vided with a U-shaped groove in the topwall of the container neck, the U-shaped groove having sidewalls 52 us.131. 215/40, 2l5/DIG. 1 which slant outwardly and p y at an angle, the51 1m. (:1 8651! 53/00 closure being provided with Substantiallycircular radi- [58] Field of Search 2l5/DlG. l, 40 any Spaced ribsdepending from the lower surface of the top portion of the closure, theouter walls of the ribs 5 R f r Cited slanting downwardly and inwardlyat the same angle, UNlTED STATES PATENTS said ribs being undercut bytheir inner walls and 3 001 658 9/1961 Hen r 215/40 X adapted tosealingly engage the groove when said cloe 2,752,059 6/1956 Schneider215/DiG. 1 ux Sure Seated neck 3,203,571 8/1965 Plunkett 2l5/DIG. l UX 6Claims, 4 Drawing Figures PATENTED JUL 2 FIG FIG.

FIG

INVENTOR.

EUGENE N. ANTHONY BY z 22 A TTORNEY LINERLESS CLOSURE BACKGROUND OF THEINVENTION The present invention relates to container closures and moreparticularly to a unique unitary container closure and the combinationof such closure with a container the neck of which is adapted to besealingly engaged by the closure.

There has been a long standing need in the container industry for alinerless closure for containers which will provide an effective sealafter repeated and continuous use. The ideal closure should beinexpensive, difficult to damage and provide allowances for stresses andstrains which closures and containers undergo in shipment and storageand for expansion and contraction which occurs due to variations inclimatic conditions during shipment, storage and use.

Expense in the manufacture of closures can be kept to a minimum byproviding a closure of unitary construction as opposed to one wherein asealing disk is enclosed by an outer capsule. In addition, the disk typeclosures have the inherent disadvantage that the disks frequently becomedislodged from the capsule and are thus easily lost or damaged.

Many prior art closures are of unitary construction, recognizing theneed for a unitary structure, but most have failed to maintain adequatescaling properties upon repeated and constant use. Frequently, theirfailure has been due to the lack of allowances for physical variationsand particularly the failure to allow for some permanent deformation ofthe seal upon repeated opening and closing of the container. Other priorart closures, although somewhat effective, require adherence to rigidtolerances which increases their cost. The most common type of unitaryclosure is one wherein lips of varying configuration have been formed onthe underside of a cap, such lips being designed to contact a portion ofthe neck of the container to which they are applied. Examples of thistype of closure include Miller, U.S. Pat. No. 3,255,909, wherein asingle lip contacts the upper surface of a container neck; Gibson, U.S.Pat. No. 3,232,470, wherein a befurcated lip contacts the upper surfaceof the neck and overhangs the upper internal wall of the neck; Wandell,U.S. Pat. No. 3,107,022, wherein a lip contacts the internal upper edgeof the neck in yet a different manner.

Another type of closure of unitary construction is a type characterizedby the modification of the container neck to provide a structure whichcooperates with lips depending from the closure. Examples of such priorart closures include: Powers, U.S. Pat. No. 1,989,527 and Kosar, US.Pat. No. 3,428,208. Other closures, such as Herter, US. Pat. No.3,001,658 have recognized the need for modified lip and neck structuresbut have not provided a unitary closure structure.

SUMMARY OF THE INVENTION The present invention is a uniqueunitarycontainer closure and the combination of the closure with a container,the neck of which is adapted to sealingly cooperate with a pair of ribsformed on the underside of the closure when the closure is seated on thecontainer neck. More particularly, the invention relates to a containerneck provided with a groove in its upper surface which, when viewed incross section, is U-shaped with the sidewalls of the U slantingoutwardly and upwardly at an angle from the base of the U. The closureis provided with a pair of substantially circular, radially spaced ribsadapted to sealingly contact the sidewalls of the groove when theclosure is seated on the container neck.

The closure may be seated on the neck, preferably by threads, but alsoby other known means which are within the spirit and scope of thepresent invention.

In the preferred embodiment, the outer walls of the ribs which dependfrom the lower side of the top portion of the closure are parallel tothe sidewalls of the groove in the container neck in order to providesealing contact between substantial surface areas of the ribs andgroove. The ribs are preferably of greater vertical height than thedepth of the groove. Each rib is slightly undercut by its inner wall toprovide greater flexibility and insure better contact of its outer wallwith the corresponding sidewall of the neck groove. In addition, the topportion of the closure is resiliently deformable to give added assurancethat sealing contact can be maintained in spite of physical variations.

The present invention provides a closure which will reseal the containerthrough repeated usages and one in which little deformation of the ribsis required to effect a good seal. Allowances have been made to assureits effectiveness is not impaired by physical variations in closure orcontainer. Since the closure is of unitary structure, there is no dangerof losing a sealing disk and since the sealing ribs are enclosed in theupper portion of the capsule, there is little or no danger of damagingsuch sealing ribs. The allowances which have been made in the presentinvention make it unnecessary for the manufacturer to maintain extremelyhigh tolerances and thus make the present seal less expensive tomanufacture.

BRIEF DESCRIPTION OF THE DRAWING The invention will be more fullyunderstood by reference to the accompanying drawing showing thepreferred embodiment of the invention:

FIG. 1 is an exploded fragmentary cross sectional view of the upperportion of the container neck and closure with the closure in anuinseated position on neck.

FIG. 2 is a cross sectional view of the container neck and closure whenthe closure is seated on the neck.

FIG. 3 is a perspective view of the neck of the container showing thegroove in the upper surface of the container neck.

FIG. 4 is a cutaway perspective view of the closure showing theintegrally molded ribs in the closure.

DESCRIPTION OF THE PREFERRED EMBODIMENT The closure 1 of the presentinvention is made of plastic material preferably of polypropylene and isprovided with a skirt portion 2 and a top portion 3, the top portionhaving an upper surface 4 and a lower surface 5.

The container neck 6 is preferably of glass and is provided with athreaded outer surface for seating the closure and a top surface 7.Materials other than glass may be used to form the container neck ifthey are at least as hard as the material used in the closure and knownmeans other than threads may be provided to seat the closure on thecontainer neck. The top surface 7 is provided with a groove defined bysidewalls 8 and 9 as shown in FIG. 1. The groove is substantiallyU-shaped with sidewalls 8 and 9 slanting upwardly and outwardly at anangle from a line drawn vertically through the center of the base of theU. In the preferred embodiment, the angle between such a vertical lineand the respective sidewalls is approximately 45. The lower surface ofthe top portion 3 of closure 1 is provided with a plurality ofsubstantially circular ribs and 11, each having outer walls 12 and 13and inner walls 14 and 15. The ribs 10 and 11 are integrally formed withand depend from the lower surface 5 of the top portion 3.

The ribs 10 and 1 l are radially spaced on the top portion 3 of theclosure so that the midpoint between them is directly above the midpointof the base of the U- shaped groove on the container neck when theclosure is affixed to the neck.

The outer walls 12 and 13 slope downwardly and inwardly toward eachother from the lower surface 5 of the top portion 3. In the preferredembodiment, the angle made by the intersection of the outer walls 12 and13 with a line drawn vertical to the plane of the top portion is thesame as the angle at which the sidewalls 8 and 9 intersect a verticalline. Thus, in the preferred embodiment, the outer walls 12 and 13 areparallel to the sidewalls 8 and 9 when the closure 1 is threaded ontothe neck 6. By providing such parallel surfaces, it is possible for theclosure to sealingly contact the groove along a plane and to effectivelyseal without substantial distortion of the sealing ribs. This providesfor greater surface contact than found in seals having the respectivesealing surfaces meet in a point-to-point relationship and avoidspermanent deformation of the ribs.

The ribs 10 and 11 are made of a resilient material such aspolypropylene so that if the angle of contact between the ribs and thesidewalls 8 and 9 varies due to physical variations, the ribs may beresiliently distorted to provide surface-to-surface contact when theclosure is seated on the container neck. However, since distortion isnormally not required to establish such a relationship, the ribs are notpermanently distorted and thus do not lose their ability to provide asealing contact with the sidewalls of the groove.

In the preferred embodiment, the vertical height of the sealing ribs 10and 11 exceeds the vertical height of the groove in order to prevent theupper surface 7 of the neck 6 from contacting the lower surface 5 of theupper portion 3 of the closure. This feature assures that even if thesealing ribs were to become permanently distorted, the closure wouldstill have sufficient room to move downwardly on the neck to allow forthe distortion which had occurred in the ribs, and thus to effect aleak-proof seal between the respective surfaces.

The ribs 10 and 11 are also provided with inner surfaces 14 and whichrespectively slant outwardly and upwardly from the ends of the ribs tothe lower surface 5 of the upper portion 3. In the preferred emboidmentthe angle made by the intersection of inner surfaces 14 and 15 with aline drawn vertical to the plane of the top portion 4 is approximately30.

The sloping of the inner walls 14 and 15 defines a groove in the closurewhich undercuts the ribs, increasing the capability of the ribs todeform in response to pressure applied to the outer walls 12 and 13 bythe sidewalls 8 and 9. The angle at which the inner walls extendoutwardly and upwardly may be varied to provide different degrees offlexibility to the ribs for different applications and still be withinthe purpose and scope of the invention.

The angle at which the outer walls 12 and 13 extend downwardly andinwardly may also be varied as may be the angle formed by theintersection of the outer walls 12 and 13 and the inner walls 14 and 15as long as the relationship between the outer walls 12 and 13 and thesidewalls 8 and 9 is maintained.

In addition to varying the flexibility of the ribs, the undercuttinggroove also contains gases when the closure is applied to the neck. Asthe closure is seated on the neck and pressure applied to the ribs bythe sidewalls, these gases are compressed forming a pressurized chamberwithin the ribs which prevents unnecessary deformation of the ribs andprovides a pressurizing seal between the ribs and the container neck.

The ribs are also provided with rounded ends 16 in order to preventdamage to the ribs when they contact the groove in the neck or a foreignsubstance which sometimes lodges itself in the groove.

The top portion 3 of the closure is substantially flat prior to beingseated on the container neck. It is sufficiently resiliently deformable,however, that when the closure is seated on the container neck by theapplication of torque or pressure, as the case may be, the top portion 3domes upwardly as shown in FIG. 2. This doming provides sufficientbuilt-in force to compensate for any physical variations which occur inthe closure or container neck due to shipment, storage or variation inclimatic conditions.

I claim:

1. In combination:

a container having a substantially U-shaped groove about the top surfacethereof, said groove having opposite sidewalls slanting upwardly andoutwardly from each other when viewed in cross-section; and, linerlessclosure mounted on said container comprising a top portion having aperipherally depending skirt portion and a pair of concentricsubstantially circular ribs integral with and depending from said topportion, the outer walls of said ribs extending downwardly and inwardlytowards each other in a direction that is substantially parallel withthe respective sidewalls of said U-shaped groove to provide a sealingcontact along a plane between said outer walls and said sidewalls, saidclosure mounted on said container in a manner such that the top portionof said closure does not contact the top surface of said container.

2. A closure as described and claimed in claim 1 wherein the verticalheight of said ribs exceeds the vertical height of said groove.

3. A closure as described and claimed in claim 1 wherein said ribs areprovided with inner walls which extend upwardly and outwardly at anangle less than an angle which is made by the outer walls with a linevertical to said top portion.

4. A closure as described and claimed in claim 3 wherein said ribs areprovided with rounded lower ends. I

5. A closure as described and claimed in claim 4 wherein said ribs aresufficiently deformable to permit sealing contact with the sidewalls ofsaid groove where physical variations have occurred to said closure orcontainer neck.

6. A 'unitary linerless closure as described and claimed in claim 1wherein said top portion is resiliently deformable.

1. In combination: a container having a substantially U-shaped grooveabout the top surface thereof, said groove having opposite sidewallsslanting upwardly and outwardly from each other when viewed incrosssection; and, a linerless closure mounted on said containercomprising a top portion having a peripherally depending skirt portionand a pair of concentric substantially circular ribs integral with anddepending from said top portion, the outer walls of said ribs extendingdownwardly and inwardly towards each other in a direction that issubstantially parallel with the respective sidewalls of said U-shapedgroove to provide a sealing contact along a plane between said outerwalls and said sidewalls, said closure mounted on said container in amanner such that the top portion of said closure does not contact thetop surface of said container.
 2. A closure as described and claimed inclaim 1 wherein the vertical height of said ribs exceeds the verticalheight of said groove.
 3. A closure as described and claimed in claim 1wherein said ribs are provided with inner walls which extend upwardlyand outwardly at an angle less than an angle which is made by the outerwalls with a line vertical to said top portion.
 4. A closure asdescribed and claimed in claim 3 wherein said ribs are provided withrounded lower ends.
 5. A closure as described and claimed in claim 4wherein said ribs are sufficiently deformable to permit sealing contactwith the sidewalls of said groove where physical variations haveoccurred to said closure or container neck.
 6. A unitary linerlessclosure as described and claimed in claim 1 wherein said top portion isresiliently deformable.